integer_mass_index_table = { 
              "G" : 57, 
              "A": 71, 
              "S": 87, 
              "P" : 97, 
              "V" : 99, 
              "T" : 101, 
              "C" : 103, 
              "I" : 113,
              "L" : 113,
              "N" : 114,
              "D" : 115,
              "K": 128,
              "Q" : 128,
              "E" : 129,
              "M": 131,
              "H": 137,
              "F" : 147,
              "R" : 156,
              "Y" : 163,
              "W" : 186 
              }